The Simpsons famously hosted all three surviving Beatles as guest stars early in its run. All three episodes have become notable, largely because of the three and the way the show makes use of them. They're also a sign of the show's eventual longevity: attracting (and commenting on) some of the biggest forces in pop culture.
All three episodes have their charms, but bringing The Fab Four to Springfield carries singular challenges that other celebrities lack. Of the trio, the first one actually makes the best use of its guest star. Season 2, Episode 18, "Brush with Greatness" features The Beatles' Ringo Starr and a sterling idea for integrating him into the story. His bandmates' appearances couldn't quite match it.
The Beatles Were Early Simpsons Favorites
The Simpsons have the same conundrum as The Muppets in that the main characters often upstage their guest stars. That's especially the case with Season 5, Episode 1, "Homer's Barbershop Quartet," which serves as a straight-up parody of The Beatles. Homer forms a singing group called the Be Sharps with Apu, Barney and Principal Skinner, with their rise and fall echoing the story of The Fab Four. George Harrison arrives more or less to gild the lily, and while he gets the episode's best line ("it's been done," he grumbles as The Be Sharps sing on the rooftop of Moe's), he's essentially an accessory to the main joke.
The same holds true for Paul McCartney, who appears in Season 7, Episode 5, "Lisa the Vegetarian." He and his late wife Linda show up "in Apu's garden in the shade" to give Lisa advice about her freshly minted vegetarianism. Like Harrison, he gets a great joke ("if you play 'Maybe I'm Amazed' backwards, you'll hear a recipe for a really ripping lentil soup!"), but he and Linda act solely as Apu's support. Had they not been present, the episode would have changed very little.
Ringo Is Central to the Story in His Simpsons Appearance
"Brush with Greatness," on the other hand, finds the perfect way to bring a Beatle into The Simpsons' lives. With encouragement from Lisa, Marge rediscovers a lost talent for painting, which eventually earns her a commission to create a portrait of Mr. Burns. Her talent was derailed early in life after her high school art teacher derided her countless paintings of Ringo Starr, on whom she was actively crushing. She sent one to the drummer, hoping for his approval, but never heard back.
The gag -- and its place in the story -- is brilliant. Starr personally answers every piece of fan mail he's ever received, and he just hasn't worked his way up to hers yet. His reply arrives just as she despairs of finishing the commission ("I hung it on me wall!" he gushes) and it gives her the self-confidence to carry on. Her painting of a nude Mr. Burns becomes an unexpected hit, and even the deplorable subject confesses to her "I don't hate this."
It all works because it incorporates The Beatle into the story instead of just using him as a garnish. Marge's crush is an open riff on Beatlemania, and Ringo's entry into her life comes with just the right absurdity to make it memorably funny. Most importantly, he doesn't feel like he's there simply because he's Ringo. His part requires someone of his standing, but it's still Marge's story, and needs to reflect what she's going through. The Simpsons was early in its run when he arrived, and needed to keep its comedy more grounded than in later seasons. Ringo's appearance benefited immeasurably, leaving him the show's victor among his fellow Beatles.